Rosenblatt, essayist for the MacNeil/Lehrer NewsHour, is on to something here with interesting theories about why America is so singularly obsessed with the abortion issue. He speculates as to reasons: our Puritan origins, the loneliness of American life, antagonism to women's liberation and despair over the eroding national morale, which commenced during the Vietnam War. He also presents an instructive history of how societies, ancient and modern, have viewed abortion. In the U.S. doctors were the first to express opposition to abortion, he notes. They did so to wrest abortion from midwives and gain control of all medical procedures. Rosenblatt issues a plea to pro-choice and pro-life advocates for tolerance, stressing that most of the country has mixed feelings regarding the issue and that our nation has learned to live with diversity. Reasoned historical and cross-cultural discussion such as this could serve to de-escalate the hysteria. (Mar.)